Phosphonates rearrangement

A phosphate-phosphonate rearrangement process has also been explored in which a strong base is used to abstract a proton from the position adjacent to an aryl phosphate ester linkage. The product, an or f/io-phosphonopheno I, is generated in excellent yield (Figure 6.16).70 Further exploration of the variability of structure for this type of reaction seems desirable. 

By contrast, the similar phosphate-phosphonate rearrangement proceeds with retention, whether it proceeds via a tertiary56 or a secondary57 organolithium 57 or 58, as does the related amide-ketone rearrangement of 59.58 These retentive rearrangements presumably involve C=0-Li or P=0-Li coordination not possible in the Brook rearrangement. 

It has been shown that metallation of diisopropyl phosphates derived from primary aliphatic alcohols, except methanol, takes place at the alkyl as well as the isopropyl group in a ratio which is strongly influenced by steric effects. It was proposed that short-lived alkyllithium compounds were configurationally stable up to — 50°C and rearrange, with retention of configuration, into the corresponding a-hydroxyphosphonates (phosphate-phosphonate rearrangement) (Scheme 21). ... 

Janecki, T, and Bodalski, R., A convenient method for the synthesis of substituted 2-methoxycarbonyl-and 2-cyanoallylphosphonates. The allyl phosphite-allyl phosphonate rearrangement, Synthesis, 799, 1990. 

Jackson, J.A., Hammond, G.B., and Wiemer, D.F., Synthesis of a-phosphono lactones and esters through a vinyl phosphate-phosphonate rearrangement, J. Org. Chem., 54, 4750, 1989. 

The possibility of P-C bond biosynthesis for AEP through a phosphate-phosphonate rearrangement has been tested in Tetrahymena thermophila by growth on a medium containing (D)-[6,6-D2]glucose and isolation of the labelled AEP. The latter, labelled 1,1-D2, was isolated in amounts not consistent with an enzymic phosphate-phosphonate rearrangement of... 

The formation of product II has been attributed to phosphite-phosphonate rearrangement from the corresponding phosphorus (HI) intermediates of the type I [157], Its analogue 2,3-butylene phosphonic acid (R=CH(CH3)CH(CH)3) forms only phosphonate-type adducts of the type II under these conditions. 

At similar levels of substitution, the phosphonate rearranged 10-20 times faster than the corresponding suUbne (Eq. 3.1.62). The rearrangements of Cl monosub-... 

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